1. Field of the Invention
The present invention generally relates to an image-forming lens array for use in an image reading apparatus or the like. The present invention particularly relates to light-shielding treatment for such a lens array.
2. Description of the Related Art
FIG. 20 of the accompanying drawings illustrates a prior art lens array 9 to be built in an image reading apparatus such as a scanner. The lens array 9 includes an elongate holder 90, and a plurality of selfoc lenses (rod lenses) 91 held in the holder 90. The lenses 91 are arranged at a predetermined pitch longitudinally of the holder 90.
As shown in FIG. 21, light entering each selfoc lens 91 takes repetitively bent path within the lens. Therefore, with the lens array 9, it is possible to form the actual size erect image a′→b′ of an original image a→b.
In the prior art, to provide the lens array 9, the plurality of selfoc lenses 91 are individually formed. Then, by insert-molding a resin, a holder 90 may be formed to embed the plurality of selfoc lenses 91.
However, the formation of the lens array 9 with such a prior art method is troublesome, because the formation of the lenses 91 and the resin-molding of the holder 90 are carried out in separate steps. The formation of the lens array is particularly complicated because each lens 91 is very small and a large number of lenses are necessary for making one lens array. Moreover, in the prior art lens array 9, cross talk of light is likely to occur between adjacent lenses 91, which is disadvantageous.